Embodiments of this invention relate to a system, in particular for winter service vehicles, which comprises a spreader for spreading out solid spreading materials having a spreading-material container for receiving the solid spreading materials to be spread out and furthermore at least one liquid tank for arrangement within the spreading-material container. The invention furthermore relates to an accordingly adapted spreading-material container and an accordingly adapted liquid tank.
German laid-open application DE 10 2010 029 142 A1 discloses a spreader for winter service vehicles which combines three different spreading methods, namely dry-salt spreading, wet-salt spreading and pure brine spreading. Normally the brine for wet-salt spreading and pure brine spreading is located in an additional tank which is mounted for example laterally of the spreading-material container in which the spreading salt is kept. Since the additional tanks are too small for spreading pure brine over a standard spreading path of approx. 50 km, DE 10 2010 029 142 A1 proposes utilizing the spreading-material container electively as a further tank container for receiving brine. The additional tanks are retained in case wet salt is to be spread and the spreading-material container is required for receiving solid thawing materials.
Instead of employing the spreading-material container itself as a further tank container, there can alternatively be provided a liquid tank insertable into the spreading-material container, in particular in the form of a tank sack. The brine required for pure brine spreading is conveyed out of the additional tanks in the conventional manner here, and the additional tanks are automatically refilled with brine from time to time from the spreading-material container or the tank sack received therein. This is done using a pump which pumps into the additional tanks the brine received in the spreading-material container or tank sack via a hose protruding thereinto. The tank sack is formed by a flexible sheath of variable volume, so that the inner volume decreases to almost zero when the tank sack is empty, and increases accordingly when the tank sack is being filled with liquid thawing materials.
The known system is limited in its variability, however, since the additional tanks for liquid are firmly installed outside on the spreading-material container and must also be carried in the case of pure dry-salt spreading although they cannot be utilized for solid spreading materials. Even if the additional tanks were removed, a funnel shape or a downward tapering shape is necessary for complete emptying of the spreading-material container in order that the solid spreading materials can slide by gravity onto a conveying device in a floor surface of the spreading-material container and be conveyed out of the spreading-material container by means of said device. This limits the volume of the spreading-material container.
An object of the present invention is hence to propose a spreader having a spreading-material container for receiving solid spreading materials to be spread out, in combination with a liquid tank, which offers high variability with regard to the spreading-material methods at the same time as improved volume utilization.
This object is achieved by a spreader having a spreading-material container for receiving the solid spreading materials to be spread out, and at least one liquid tank for arrangement within the spreading-material container, and by an accordingly adapted spreading-material container and an accordingly adapted liquid tank, having the features of the independent claims. Claims dependent thereon state advantageous embodiments and developments of the invention.
According to the invention there is provided a spreading-material container which has a horizontal or almost horizontal floor surface and a conveying device, for example a screw conveyor, which extends within the horizontal or almost horizontal floor surface. On or above the floor surface there is arranged within the spreading-material container at least one liquid tank so as to form, upon an at least partial filling of the liquid tank, a sliding surface for the solid spreading materials to be spread out that is inclined toward the conveying device relative to the floor surface. The inclined sliding surfaces thus limit within the spreading-material container a spreading-material volume that is variable through filling and emptying of the at least one liquid tank. When the liquid tank is empty, substantially the total volume of the spreading-material container can be utilized for solid spreading materials.
The employment of a spreading-material container having a horizontal or almost horizontal floor surface instead of a funnel-shaped spreading-material container enables optimal utilization of the available volume of the spreader, which can be placed for example on a truck loading surface. On the one hand, substantially the total volume of the spreading-material container can be utilized for solid spreading materials for pure dry-salt spreading when the liquid tank has been emptied. Thus, more solid spreading material can be received in the spreading-material container than in a funnel-shaped container. This is possible since an inclined sliding surface can be formed by filling the at least one liquid tank with air. That is to say, while solid spreading materials are being spread out from the spreading-material container, the liquid tank is gradually inflated and the inclination of the sliding surface changed. This guarantees a complete emptying of the spreading-material container in spite of the horizontal or almost horizontal floor surface of the spreading-material container. On the other hand, wet-salt spreading can be effected when the liquid tank is partly filled with brine and the remaining volume of the spreading-material container is filled up with solid spreading materials. Here, too, an emptying of the solid spreading materials is ensured due to the sliding surface formed by the liquid tank. If the liquid tank collapses due to the successive withdrawal of brine to the extent that the inclination of the sliding surface becomes insufficient, the liquid tank can be filled up with air accordingly again. Pure brine spreading is also possible when the at least one liquid tank is filled to the extent that it occupies approximately the total volume of the spreading-material container.
In every case it is thus possible to optimally utilize the volume of the spreading-material container, which volume can be in particular cuboid or almost cuboid due to the horizontal or almost horizontal floor surface. In particular, it can be utilized substantially completely either only for solid spreading materials or only for brine or else also for solid spreading materials and brine with fully variable volume portions of the spreading-material container respectively substantially of 0-100%. Spreading-material containers having a horizontal or almost horizontal floor surface are moreover cheaper, since their shape with substantially mutually perpendicular side walls is simpler to manufacture than a funnel shape. Also, no exterior additional tanks or connected vent valves are necessary, and less piping, which simplifies the structure of the system as a whole and saves costs. A further advantage results from the fact that the liquid tanks can be replaced cost-efficiently.
A spreading-material container having a horizontal or almost horizontal floor surface is understood to be in particular a spreading-material container whose floor surface has an inclination relative to the horizontal that is so small as to allow no or almost no independent sliding by gravity of solid spreading materials. For example, the floor surface can have in every region an inclination of less than 20° relative to the horizontal. The floor surface can be inclined toward the conveying device as well as away therefrom. Since the inclined sliding surface is formed by the at least one liquid tank and not by the floor surface, a complete emptying of the spreading-material container is nevertheless possible. Further, a cuboid or almost cuboid spreading-material container is understood to be a spreading-material container having a horizontal or almost horizontal floor surface and substantially vertical side walls. The side walls can also have a certain inclination, for example up to no more than 20° relative to the vertical. The shape of the upper side of the spreading-material container is inessential to the invention. The upper side can likewise be configured horizontally or almost horizontally, or else have an arbitrary shape, for example a roof shape allowing precipitation to flow off.
In the spreading-material container there can be provided in particular two liquid tanks which are arranged on or above the floor surface on opposing sides of the conveying device. The conveying device can be arranged in the floor surface of the spreading-material container for example substantially in the middle and running in the longitudinal direction. In this way the inclined sliding surfaces can obtain a funnel shape of the spreading-material volume. The following remarks are thus respectively to be understood in particular also for mutually opposing liquid tanks.
Preferably, the at least one liquid tank is configured to remain within the spreading-material container when in the completely emptied state, while solid spreading materials to be spread out can be simultaneously received in the spreading-material container and spread out by means of the spreader. The volume of the spreading-material container can in this case be utilized for solid spreading materials completely or almost completely, i.e. up to 100%, preferably at least 90%, but at least 80%. The liquid tank thus need not be taken out of the spreading-material container when pure dry-salt spreading is to be effected. This is promoted in particular by the flexible sheath of the liquid tank, which enables the liquid tank to collapse or fold up. Furthermore, the liquid tank can have a plate or fixed frame or comprise a stiff material on its side facing the spreading-material container wall, so as to guarantee that the liquid tank adjoins the spreading-material container wall when folding up or collapsing and accordingly does not block the conveying device on the bottom of the spreading-material container in the emptied state.
If the inclined sliding surface is formed by the liquid tank itself, its flexible sheath can cause creasing to occur upon an only partial filling of the liquid tank. In particular when the liquid tank collapses during emptying, creases can arise in which solid spreading materials located in the spreading-material container settle, thereby impeding the emptying of the spreading-material container. Hence, it is advantageous to provide at least one movable plate to form the sliding surface. The at least one movable plate is preferably so arranged in the spreading-material container, or can be so arranged in the spreading-material container, that the at least one liquid tank is located between the floor surface and/or a side surface of the spreading-material container and the at least one movable plate. The inclined sliding surface is thus formed at least partly by a surface of the at least one movable plate. The liquid-tank surface which can tend to crease is covered by the at least one movable plate. The plate is movable, so as to retain the variability of the volume of the liquid tank through changing of the liquid-tank filling. The position of the at least one movable plate thus depends on the fill quantity of the liquid tank, in particular when the plates are not moved actively, for example by electric motor, pneumatically or hydraulically, but are freely movable and rest on the at least one liquid tank due to gravity. It is also possible, however, to move the at least one movable plate actively, in which case corresponding actuators and a corresponding control means are to be provided.
Preferably, the at least one movable plate is connected in an articulated manner to the spreading-material container such that solid spreading materials received in the spreading-material container slide by gravity along the inclined sliding surface to the conveying device in the floor surface of the spreading-material container. However, the at least one movable plate can alternatively or additionally also be firmly connected to the liquid tank. Through a preferably rigid plate as part of the spreading-material container and/or of the liquid tank, a smooth sliding surface is present at all times so as to facilitate a sliding of the solid spreading material along the sliding surface.
In a preferred embodiment of the invention, at least two movable plates are provided. At least one of the movable plates is arranged in an upper region of the spreading-material container so as to swivel around a horizontal rotation axis, and at least one further one of the movable plates is arranged so as to swivel around a rotation axis parallel thereto in a lower region of the spreading-material container. Through the provision of two cooperating movable plates, the volume of the liquid tank can be enlarged in comparison to an embodiment with only one movable plate, since a quadrangular cross-sectional shape of the liquid tank can be obtained. If only one plate is provided, it must necessarily be configured relatively long so as to form a sufficiently long sliding surface. Due to the limited volume of the spreading-material container, however, this restricts the swivel angle of the plate. If at least two plates are provided, they can be shorter and accordingly be swiveled further. It is advantageous here when the plate linked in the upper region overlaps the plate linked in the lower region and lies above the plate linked below so as to keep solid spreading materials from passing between and under the plates. For this purpose there can for example also be provided a seal, such as a sealing blanket, between the two plates.
Further preferably, there can also be provided at least two movable plates that are interconnected in an articulated manner. This further increases the variability of the volume of the liquid tank and of the spreading-material container. For example, there can be provided three movable plates, one being arranged in a lower region of the spreading-material container so as to swivel around a horizontal rotation axis, and a second plate being arranged in an upper region of the spreading-material container so as to swivel around a rotation axis parallel thereto, the third plate being attachable in an articulated manner to the free end of the upper plate. This makes it possible to enclose with the plates a volume having a pentagonal cross section for the liquid tank.
Preferably, a plurality of movable plates are configured such that they can jointly enclose a cuboid or prism-shaped volume portion of the volume of the spreading-material container in which the liquid tank is housed. A prism shape, in particular a triangular, quadrangular or pentagonal prism, can be obtained for example by a multi-part plate or by a plurality of plates interconnected in an articulated manner which are connected to the spreading-material container in an accordingly articulated manner. For forming a cuboid shape, two movable plates are required. By a corresponding choice of the plates, in particular their shape, dimensions and connections to the spreading-material container, liquid tank and/or to each other, there can thus be obtained a high variability of the spreading-material volume and of the liquid volume.
Preferably, the at least one movable plate is sealed against the spreading-material container so as to prevent spreading materials received in the spreading-material container from passing onto a side of the movable plate that faces away from the sliding surface. A seal against the corresponding side walls of the spreading-material container is expedient in particular on edges of the plates that border on the rotation axes, in order that the spreading materials do not pass under the movable plates, which would necessitate elaborate cleaning, since spreading materials that have passed under the plates cannot be captured by the conveying device and conveyed out of the spreading-material container. The seal can be effected through corresponding seals, for example sealing lips, which slide along the corresponding side wall of the spreading-material container upon a motion of the plates.
In a preferred embodiment of the invention, the liquid tank has arranged therein an expandable apparatus which advantageously consists at least partly of an elastic material, so that the expandable apparatus can expand in a balloon-like manner. In this way it is possible to maintain the inclined sliding surface even when no or only little liquid is received in the liquid tank. The expandable apparatus is for this purpose preferably arranged in the liquid tank in a lower region, in particular near the floor surface of the spreading-material container, and can be configured as an inflatable sack or balloon.
In particular, the volume of the liquid tank as a whole can be maintained even during the emptying of the liquid tank by expanding the expandable apparatus to the same extent as liquid is withdrawn from the liquid tank. When the liquid received in the liquid tank is always held in the upper region of the liquid tank, the liquid tank can advantageously be emptied without the use of a pump only by utilizing hydrostatic forces and, where applicable, a regulating valve, whereby for this purpose the connection for emptying the liquid tank is located in its upper region. This is advantageous at least in spreading operations that require no pressure for applying the liquid. The same effect can also be achieved when the volume withdrawn from the liquid tank is compensated by air which is pumped into the liquid tank upon emptying of the liquid tank. For this purpose, a pressure valve is advantageous in both cases in order to enable a pressure to be built up in the liquid tank or in the expandable apparatus.
According to a particularly preferred embodiment of the invention, the liquid tank consists of an elastic material, in particular a latex, which, upon filling, stretches and adapts to the shape of the spreading-material container. In the emptied state the tank sack then occupies particularly little room. The elastic stretchability of the material as intended by the invention amounts to more than 20%, preferably more than 50% and particularly preferably more than 100%. The liquid tank can thus expand in a balloon-like manner in this preferred embodiment.
The system according to the invention enables a simple emptying of the spreading-material container, since spreading materials received in the spreading-material container can slide along the sliding surface in the direction of the conveying device. To enable emptying even when the spreading materials have become stuck, the at least one liquid tank and/or, where applicable, the expandable apparatus can be at least partly filled and emptied in a pulsating manner so as to loosen spreading materials received in the spreading-material container. Such filling can be effected either with air, in particular compressed air. When an expandable apparatus, such as an inflatable balloon, is provided in the liquid tank, for example compressed air can be pumped into the balloon and let out again in a pulsating manner. Spreading materials received in the spreading-material container can be loosened in this way so as to prevent for example a tunnel or bridge from forming or—if one has already come about—to dissolve it. This problem occurs when the conveying device on the floor of the spreading-material container conveys spreading materials away and no spreading materials follow.
It can also be advantageous to heat the spreading materials to be spread out before spreading them out on the road in order to improve their adhesion to ice and their thawing effect. For this purpose, spreading materials received in the spreading-material container can be heated by at least partly filling the at least one liquid tank with a heated fluid before the emptying of the spreading-material container. For example, the brine can be heated before being filled into the liquid tanks, thereby simultaneously heating the solid spreading materials, since the liquid tank is located in the spreading-material container. It is advantageous to heat the brine by means of a continuous-flow heater upon application to the road, since this can guarantee that the brine has a desired temperature upon application. If the brine is only heated before or during filling, the heated brine can cool down in the course of time due to the lack of heat insulation of the tank.